Intraocular pressure rise is predictive of vision improvement after intravitreal triamcinolone acetonide for diabetic macular oedema: a retrospective analysis of data from a randomised controlled trial
BMC Ophthalmology
Intraocular pressure rise is predictive of vision improvement after intravitreal triamcinolone acetonide for diabetic macular oedema: a retrospective analysis of data from a randomised controlled trial
Roderick F O'Day 0
Daniel Barthelmes 0
Meidong Zhu 0
Tien Y Wong 1 2
Ian L McAllister 4
Jennifer J Arnold 3
Mark C Gillies 0
0 Clinical Ophthalmology & Eye Health, The University of Sydney , Sydney , Australia
1 Centre for Eye Research Australia, University of Melbourne , Melbourne , Australia
2 Singapore Eye Research Institute, National University of Singapore , Singapore, Singapore
3 Marsden Eye Specialists , Sydney , Australia
4 Lions Eye Institute, University of Western Australia , Perth , Australia
Background: Intravitreal triamcinolone acetonide (IVTA) is an effective treatment for recalcitrant diabetic macular oedema (DMO). It has been shown to improve vision with benefits persisting up to five years. The most common initial side effect of IVTA treatment is rise in intraocular pressure, occurring in approximately 50% of patients within the first 6 months of treatment. We evaluated whether there is a correlation between the development of intraocular pressure rise and improvement in vision. Methods: Analysis of individual data from 33 eyes of 33 participants treated with IVTA for DMO from a prospective, randomised, double-masked, placebo controlled trial. The degree of intraocular pressure (IOP) rise was correlated with improvement in best-corrected visual acuity (BCVA) at 1 and 6 months. Results: The proportion of eyes gaining 5 or more logMAR letters was higher in eyes with greater IOP rise (p = 0.044). Better absolute improvement in BCVA at 6 months (p = 0.045) was also found in eyes with greater IOP rise. Regression analyses revealed a correlation between IOP rise of 10 or more mmHg and absolute BCVA improvement at 6 months (odds ratio 1.22, 95% confidence interval 1.01-1.48, p = 0.039), but not at 1 month. Conclusions: IOP rise and vision improvement appear to be correlated following IVTA for DMO, suggesting that the mechanisms that cause both may be linked.
Intravitreal triamcinolone; Diabetic macular oedema; Vision improvement; Intraocular pressure rise; Adverse events; Efficacy
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Background
The treatment of diabetic macular oedema (DMO), the
commonest cause of vision loss in people with diabetes,
is rapidly evolving [1]. The past ten years have seen a
progressive shift away from laser photocoagulation
therapy with the emergence of new pharmacotherapeutic
approaches. Much of the recent focus has been on
intravitreal inhibitors of vascular endothelial growth factor
(VEGF). These are rapidly becoming the standard of
care for diffuse DMO [2]. VEGF inhibitors are generally
well tolerated, however, potentially significant systemic
and ocular side effects have not been comprehensively
excluded [3,4]. In particular, it has been suggested that
VEGF may play a neuroprotective role, the inhibition of
which may lead to loss of vision in the long-term [5].
Intravitreal triamcinolone (IVTA) is another proven
treatment for recalcitrant DMO with well-known side-effects
[6-12]. In patients with persistent DMO despite laser
treatment, intravitreal injections of triamcinolone acetonide
were shown to improve vision and reduce macular
thickness with benefits persisting up to five years [6-8]. In that
study, IVTA treatment doubled the chance of visual acuity
improvement and halved the chance of deterioration in eyes
with advanced DMO [6-8].
The ocular safety of IVTA treatment has been
thoroughly explored [6-8,13-16]. The most common adverse
events of IVTA treatment are intraocular pressure (IOP)
rise and accelerated cataract formation, particularly
posterior subcapsular cataract. Reported rates of IOP rise
differ; in our study approximately 50% of eyes had an
IOP rise of 5 or more mmHg within the first six months
of IVTA treatment [6-8]. IOP rise has been shown to be
significantly associated with cataract progression,
suggesting that these steroid-related adverse events may
have similar aetiologies, for example genetic
polymorphisms in the steroid receptor [15]. In this study, we
analysed whether IOP rise was linked with visual acuity
improvement using data from the Triamcinolone for
Diabetic Macular Oedema (TDMO) study [6-8]. If so,
this would suggest that the mechanisms of IOP rise and
vision improvement after IVTA for DMO are similar
and may help to further advance our understanding of
how IVTA acts on macular oedema.
Methods
This analysis is based on data from the TDMO study,
which was the first major prospective, randomised,
double masked, placebo-controlled clinical trial to test
the hypothesis that IVTA safely improves visual acuity
in eyes with advanced DMO over 2 years [6-8]. For the
TDMO study, patients were recruited from a major
tertiary referral centre. Inclusion criteria were persistent
diabetic macular oedema involving the central fovea
persisting three months or more after a (...truncated)